/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.zookeeper;

import java.util.List;

import jline.Completor;

class JLineZNodeCompletor implements Completor {
	private ZooKeeper zk;

	public JLineZNodeCompletor(ZooKeeper zk) {
		this.zk = zk;
	}

	@SuppressWarnings("unchecked")
	public int complete(String buffer, int cursor, List candidates) {
		// Guarantee that the final token is the one we're expanding
		buffer = buffer.substring(0, cursor);
		String token = "";
		if (!buffer.endsWith(" ")) {
			String[] tokens = buffer.split(" ");
			if (tokens.length != 0) {
				token = tokens[tokens.length - 1];
			}
		}

		if (token.startsWith("/")) {
			return completeZNode(buffer, token, candidates);
		}
		return completeCommand(buffer, token, candidates);
	}

	private int completeCommand(String buffer, String token, List<String> candidates) {
		for (String cmd : ZooKeeperMain.getCommands()) {
			if (cmd.startsWith(token)) {
				candidates.add(cmd);
			}
		}
		return buffer.lastIndexOf(" ") + 1;
	}

	private int completeZNode(String buffer, String token, List<String> candidates) {
		String path = token;
		int idx = path.lastIndexOf("/") + 1;
		String prefix = path.substring(idx);
		try {
			// Only the root path can end in a /, so strip it off every other prefix
			String dir = idx == 1 ? "/" : path.substring(0, idx - 1);
			List<String> children = zk.getChildren(dir, false);
			for (String child : children) {
				if (child.startsWith(prefix)) {
					candidates.add(child);
				}
			}
		} catch (InterruptedException e) {
			return 0;
		} catch (KeeperException e) {
			return 0;
		}
		return candidates.size() == 0 ? buffer.length() : buffer.lastIndexOf("/") + 1;
	}
}
